The present invention relates to the field of combustion technology, and more particularly, to burners utilized for mixing gas and air to form a flame for use in industrial boilers and heaters.
The efficient and economical operation of industrial boilers and heaters requires that the burners utilized not only provide the requisite level of heat, but do so utilizing as little of both fuel and excess air as possible. If burners do not combust efficiently on account of poor mixing of fuel and air prior to combustion, the combustion will be incomplete and will result in wasted fuel and the unwanted production of carbon monoxide. The velocity of air through an industrial burner increases turbulence, which assists in the proper mixing of gas and air to allow for complete combustion. However, higher levels of excess air reduce the heat transfer efficiency of the boiler or heater, causing an increase in fuel consumption. Therefore, the optimal burner design, which has not been achieved, is one that is not only able to properly mix air and fuel for complete combustion at the lowest possible air flow, but also has the advantages of being economical to manufacture, assemble and use in industrial boilers, industrial heaters and the like. What is needed is an improved industrial burner assembly that overcomes the limitations of the prior art.
It is an object of the present invention to provide an improved burner assembly for use in industrial boilers and heaters.
Another object of the present invention is to provide a burner that causes natural gas and other gaseous fuels to mix more thoroughly prior to combustion, reducing excess air demands and increasing industrial boiler and heater fuel efficiency.
A still further object of the present invention is to provide an industrial burner assembly that burns natural gas and other gaseous fuels more completely than conventional industrial burners.
An additional object of the present invention is to provide an industrial burner that is easy and inexpensive to manufacture and assemble.
These and other objects of the present invention are accomplished through the use of an industrial burner assembly for mixing gas and air to form a flame for use in an industrial boiler, an industrial heater or the like. The present invention comprises one or more elongated burners having a cylindrical outer mixing tube with a longitudinal axis, an inner mixing tube positioned coaxially about the longitudinal axis within the outer mixing tube to form an annular space therebetween. The inner mixing tube of the present invention has an inner surface defining an air flow passage through the burner, and also a plurality of apertures through which a fuel such as natural gas is introduced into the flow passage from the annular space. In the preferred embodiment, the apertures are tangentially angled to impart a swirl to the air and fuel flowing through the passage to enhance mixing of fuel and air prior to combustion.
The present invention also provides a fuel port communicating with the annular space for supplying a fuel thereto. From the annular space, the fuel flows through the inner mixing tube apertures into the flow passage where it mixes with air. The present invention further comprises a vortex plate connected across a centrally-located inlet opening of the inner mixing tube to swirl air flowing through the passage. The preferred embodiment comprises four elongated burners positioned radially about a centrally located manifold in communication with the fuel ports of each elongated burner.
These and other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment of the invention.